The present invention is related to systems and methods for detecting and/or decoding information, and more particularly to systems and methods for performing noise predictive filtering.
Various data transfer systems have been developed including storage systems, cellular telephone systems, and radio transmission systems. In each of the systems data is transferred from a sender to a receiver via some medium. For example, in a storage system, data is sent from a sender (i.e., a write function) to a receiver (i.e., a read function) via a storage medium. The effectiveness of any transfer is impacted by any data losses caused by various factors. In some cases, an encoding/decoding process is used to enhance the ability to detect a data error and to correct such data errors. As an example, a simple data detection and decode may be performed, however, such a simple process often lacks the capability to converge on a corrected data stream.
To heighten the possibility of convergence, noise predictive filtering may be used. Turning to FIG. 1, an exemplary prior art data processing circuit 100 including a noise predictive calibration circuit 150 is depicted. Data processing circuit 100 receives a data input 105 that is applied to a an analog front end circuit 110 that yields an analog output 115. Analog output 115 is provided to an analog to digital converter circuit 120 where it is sampled to generate a series of digital samples 125. Digital samples 125 are equalized using an equalizer circuit 130, and a resulting equalized output 135 is provided to both a data detector circuit 140 and a noise predictive calculation circuit 150. Data detector circuit 140 applies a data detection algorithm to yield an output 145. Both output 145 and equalized output 135 are used by noise predictive calibration circuit 150. Noise predictive calibration circuit 150 provides a noise predictive output 155 to data detector circuit 140 that is used to guide the detection algorithm. In some cases, such noise predictive filtering is not sufficiently effective to yield convergence, and/or is costly in terms of area and power.
Hence, for at least the aforementioned reasons, there exists a need in the art for advanced systems and methods for data processing.